Inspection of Steel Bridge Components using Nondestructive Evaluation

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Lewis Beasley
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1 Inspection of Steel Bridge Components using Nondestructive Evaluation Shane D. Boone, Ph.D. Federal Highway Administration Pranaam Haldipur, Ph.D. Engineering &Software Consultants, Inc. (ESCINC) Under FHWA Contract # DTFH61 08 D 00014

2 Slip Testing of Steel Bridge Coatings Justin Ocel, PhD P.E FHWA - Author Office of Infrastructure R&D Structural Steel Research Program Manager Louis N. Triandafilou, P.E. FHWA - Presenter Office of Infrastructure R&D Team Leader Bridge & Foundation Engineering Team 1

3 Design of Slip-Critical Connections Class A : unpainted clean mill scale, or coating equivalent Class B: unpainted blastcleaned surfaces, or coating equivalent Class C: not relevant to this presentation.

4 Concerns of a Fabricator If you re going to paint, you want to avoid masking So, The coating (i.e. primer) on the faying surface must meet the assumption of the designer in terms of a slip coefficient (i.e. Class A or B)

5 Big Deal, Who Cares Some organic zinc rich coatings no longer meet Class B performance Paint manufactures claim no change in formulation Paint manufactures blame the testing agencies Testing agencies blame the testing specification Welcome to my Nightmare on Elm Street Dee McNeil Sherwin-Williams

6 Test Procedure Appendix A, Specification for Structural Joints Using High-Strength Bolts

9 Test Matrix 1. Round Robin Testing 4 labs FHWA-TFHRC, KTA-Tator, CCC&L, UT-Austin 2. Five Organic Zinc-Rich Primers PPG Amercoat 68HS Sherwin-Williams Zinc-Clad III HS Carboline Carbozinc 859 Wasser MC 100 Zinc International Interzinc 315B 3. Two Thicknesses +1 mil +2 mil

10 Results Product A (Max +1) - TFHRC Load (kips) A1 A2 A3 A4 A5 A6X Slip (inches)

11 Results Product A (Max +1) CCC&L

12 Results Product A (Max +1) Specimen Lab 1 Lab 2 Lab Average Class A Class A Class B

13 Results Product A (Max +2) Specimen Lab 1 Lab 2 Lab Average Class A Class A Class B

14 Results Product B (Max +1) Specimen Lab 1 Lab 2 Lab Average Class B Class B

15 Closing Thoughts on Round Robin We re still testing every two weeks between the four labs No firm recommendations as of yet for RCSC consideration, likely better idea by Summer 2014

16 Slip Coefficient Testing of Metallized/Sealed Coatings 15

17 What is Metallizing? Profiled Steel Substrate Slide taken from Joe Bracken (PennDOT) presentation Galvanizing versus Metallizing of Structural Steel 2013 QAW in Williamsburg, VA

18 Test Matrix Preliminary study looking at slip and creep testing of metallized coatings 100% Zn and 85% Zn/15% Al w/ and w/o sealer

19 Slip Results Specimen 100% Zn (avg mil) (unsealed) 100% Zn (avg mil) (sealed with Carboline Rustbond Epoxy Penetrating Sealer, avg. 1.4 mil DFT) 85% Zn/15% Al (avg mil) (unsealed) 85% Zn/15% Al (avg mil) (sealed with Carboline Rustbond Epoxy Penetrating Sealer avg. 1.2 mil DFT) Slip Factor > (Class A) > (Class A)

20 Creep Results Specimen 100% Zn (avg mil) (unsealed) 100% Zn (avg mil) (sealed with Carboline Rustbond Epoxy Penetrating Sealer, avg. 1.4 mil DFT) 85% Zn/15% Al (avg mil) (unsealed) 85% Zn/15% Al (avg mil) (sealed with Carboline Rustbond Epoxy Penetrating Sealer avg. 1.2 mil DFT) Creep PASS FAIL PASS FAIL

21 Closing Thoughts on Metallizing Slip/Creep Limited data collected warrants further exploration, Ocel trying to secure internal funding for further testing

22 ?? Questions??

23 Overview Inspection of Transition Butt Welds using Phased Array Ultrasonic Testing Goal was to compare UT, PAUT, and RT inspection results Currently testing three transition butt weld specimens Protocols for shop and field testing Inspection of Multi Plate Gusset Connections using Pulsed X ray NTSB Report Protocols for field testing

24 Inspection of Transition Butt Welds using Phased Array Ultrasonic Testing

25 SCAN PLAN FOR TRANSITION BUTT WELDS 4

26 SCAN PLAN FOR TEST SPECIMEN TP3

27 Weld C L 1 st Leg data 3.1 S-SCAN S-scan view of data from 1 st leg

28 S-SCAN 0 S-scan view of data from 2 nd leg

29 PAUT Probe Volume Corrected C scan 8

30 PAUT Vs RT Specimen Transition Butt weld :TP1 9

31 PAUT Vs RT Specimen Transition Butt weld : ESW

32 PAUT Vs RT Specimen Transition Butt weld : SAW

33 PAUT Results from Transition Butt Welds Specimen TP1: 4 clusters of slag and inclusions and one large inclusion Specimen ESW 1 2 : Two clusters of slag Specimen SAW 1 2 : A cluster of porosity and a cluster of slag. 12

34 Conclusions and Future Work Volume corrected C scans can be directly correlated to Radiography Demonstrated ability to size flaws accurately using PAUT data. Future work will involve inspecting a larger set of butt weld and transition butt weld specimens with round robin type testing Development of protocols for specific weld types and joint configurations.

35 Inspection of Multi Plate Gusset Connections using Pulsed X ray

36 National Transportation Safety Board (NTSB) I 35W Bridge collapse Accident Report NTSB/HAR 08/03 [1] recommendation H was to: require that bridge owners assess the truss bridges in their inventories to identify locations where visual inspections may not detect gusset plate corrosion and where, therefore, appropriate Non Destructive Evaluation technologies should be used to assess gusset plate condition. 15

37 Mockup Specimen, L8 Joint 16

38 Mockup Specimen, L8 Joint 17

39 X ray Imaging with Pulsed Collimated Source Pulsed X ray sources produce radiation only when source is active X rays are highly directional Sources are portable and can be operated using batteries equivalent to those used in electric screwdrivers Orthotropic crystal imaging plates 18

40 Each gusset was examined separately Exploited the flexible plate construction to inspect hard to access regions Also, angled source when appropriate This smears images but allows inspection of hard to access areas

43 Imaging Results

44 Conclusions and Future Work Pulsed X ray technique found to be most appropriate for detection of corrosion damage in multi plate gusset members (also tried multiple ultrasonic methods) Refine the X ray technique to allow for sizing of damage when flexible film is folded to fit in areas of limited access Evaluate different pulsed X ray sources for thicker specimen Develop stand alone analysis software for both approaches. 23

SLIP CRITICAL JOINTS

SLIP CRITICAL JOINTS Joints subject to fatigue load with reversal of loading directions Joints that utilize oversize holes Joints that utilize slotted holes Joints in which slip at the faying surfaces